[U-Boot-Users] Boot Sequence

Firmware firmware at tasksistemas.com.br
Tue Aug 8 14:33:34 CEST 2006


Hi,

I would like to ask a specific question for the ARM processor at91rm9200.

I have a custumize ARM board that uses two ARM flash model AT49BV64 ( each
one is 8 Mbytes ) and two sdram model 48lc8m16a (each one is 16 M Bytes), it
looks like an at91rm9200ek board, but the FLASH are not the same.

The first FLASH address is 0x1000.0000.
The second FLASH address is 0x3000.0000.
The RAM Adress is 0x2000.0000.
In the first flash I have the uboot ( 0x1000.8000 ), the kernel(
0x1004.0000) and the ramdisk ( 0x1024.0000 ).

Right now I am using uboot 1.1.3, as far as I know it was modified to meet
the board hardware?!

When the system boots up, the first thing that the system do is copy the
uboot from the FLASH to the RAM at the adress 0x21f0.0000, and after that
uboot programs is running in the RAM.

U-Boot> printenv
bootdelay=3
baudrate=115200
bootargs=root=/dev/ram=rw initrd=0x21100000,6000000 ramdisk_size=15360
bootcmd=bootm 10040000 10240000
ethaddr="ca:zz:om:ar:in:oo
stdin=serial
stdout=serial
stderr=serial
filesize=BEC5B

The uboot program calls the kernel and the startup process keeps going on

For test purposes, I will update the Uboot to 1.1.4

I am using ELDK 4.0 and the last u-boot version, but there are some 
questions regarding boot process that I would like to know.

1) What is the physical address of the saved U-BOOT PROGRAM and the 
ENVIROMENT VARIABLES ( I am using enviroment size 4096 bytes ) in the flash 
?

2) When we do boot the system thru xmodem, we send the loader.bin and after 
that the u-boot.bin, on the ARM doc there is a reference for the program 
boot.bin, what is the boot.bin for?


Regards,

Carlos 





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